Self-erecting derrick



Feb. 12, 1957 J. P. SELBERG Er AL 2,731,108

SELF-ERECTING DERRICK Original Filed May 4, 1.950 9 Sheets-Sheet l Feb.12, 1957 J. P. sx-:LBERG ET AL 2,781,108

SELF-ERECTING DERRICK 4 Original Filed May 4, 1950 9 Sheets-Sheet 2@wma/@ Feb. 12, 1957 J. P. sELBERG Er AL SELF-ERECTING DERRICK.

9 Sheets-Sheet 5 Original Filed May 4, 1950 Feb. 12, 1.957 .1. P.sELBERG E'r AL "2,781,108

SELF-ERECTING DERRICK 9 Sheets-Sheet 4 Original Fled- May 4, 1950 Feb.12, 1957 J. P. sELBERG Er AL 2,781,108

SELF-ERECTING DERRICK Original Filed May 4, 1950 9 Sheets-Sheet 5 f/zven or JohnPSeZ will liant/15G?? i Z Feb. 12, 1957 1. P. SELBERG Er AL2,731,108

SELF-ERECTING DERRICK `original Filed may 4, 195o s sheets-sheet e Feb.12, 1957 J. SELBERG ErAL 2,781,108

SELF-ERECTING pERRIcK.

9 Sheets-Sheet 7 Original Filed May 4, 1950 Feb. 12, 1957 J. P. sELBERGET Al. 2,781,108

SELF-ERECTING DERRICK 9 Sheets-Sheet 8 Original Filed May 4, 1950 Feb.12, 1957 J. P. sELBERG Er AL 2,781,108

SELF-ERECTING DERRICK Original Filed May 4, 1950 l 9 Sheets-Sheet 9United States SELF-ERECHNG Draaien John P. Selberg, North Hollywood, andWilliam H. Grifiiih, Oakland, Calif., assignors, by mesne assiwments, toDresser Equipment Company, Dallas, Tex., a corporation of OhioContinuation of application Serial No. 160,044, May 4, 1950. Thisapplication March 30, 1956, Serial No. 575,027

15 Claims. (ci. rsa- 15) This invention relates to well drilling rigs,and has particular reference to a self-erecting transportable derrickwhich nds particular utility when employed for the rotary drilling ofdeep wells such as oil and gas wells. This application is a continuationof application Serial Number 160,044, filed May 4, 1950, now abandoned.

In the rotary drilling of deep wells, it is the general practice toerect at each well site a tall drilling derrick, the primary function ofwhich is to provide hoisting and handling equipment for manipulating thedrill string and drilling tools used during the drilling of the well.Once the well is brought into production, the tall drilling derrick isno longer required and is oftentimes dismantled and removed entirelyfrom the well site, portable derricks being brought in from time to timeWhenever it is necessary to service the well pumping equipment.

Prior to this invention it was the general practice to erect suchdrilling derricks on the site, a piece at a time, the entire structurebeing fabricated and erected on the drilling site. Since such derricksare very tall, ranging upwards from 120 feet in height, the time andcost of erecting and then later dismantling such derrick structures issubstantial.

Because of the time required to construct and dismantle drillingderricks of the 'character mentioned, a need has been felt for aprefabricated derrick structure which could be erected at the well sitein a relatively short time and which was susceptible to being loweredand readily transported to a new site when the well was completed.Transportable derricks of this type are particularly desirable where anumber of wells are to be drilled in succession in relatively adjacentlocations. In an attempt to meet this need, a number of different typesof portable derricks have been devised, the derrick shown in the patentto F. A. Funk, No. 2,345,253, issued March 28, 1944, beingrepresentative.

The transportable derricks devised prior to this invention are allcharacterized by certain disadvantages, the most notable of which istheir lack of suiiicient strength and rigidity required to meetsatisfactorily the extremely heavy service requirements imposed upondrilling derricks when deep wells are drilled. This deficiency is met inpart in some installations by the installation of a elaborate andexpensive system of guy lines with their attendant disadvantages.Furthermore, most of the portable derricks known prior to this inventionare of relatively limited height requiring the drill stem to beseparated into stands comprising two lengths of drill pipe asdistinguished from the three and four lengths of drill pipe going into astand as used with conventional drilling derricks. The necessity forseparating the drill stem into such relatively short standssubstantially doubles the amount of work required in running a drillstring into the hole and in removing the drill string from the hole whenit is necessary to replace the drilling bit. Since' a large percentageof the drilling time is used in running the drill string into and out ofthe hole, this substantial doubling of that portion of the time greatlyextends the length of time required to drill the oil well andconsequently correspondingly increases the loss of production and thecost of the well.

Additionally, the transportable derricks devised prior to this inventionembody a construction and arrangement of parts and facilities which issubstantially different from the arrangement found on standard drillingrigs, making it necessary to use somewhat modified drilling proceduresin the operation of the rigs. This makes it necessary to teach thedrilling crews new procedures using instrumentalities with which theyare not entirely familiar, with a corresponding loss of eiciency andincrease in cost.

Furthermore, the erection of the portable derricks devised prior to thisinvention is attended by considerable hazard. For example, thosederricks which are erected from a horizontal position to a verticalposition by hinging a prefabricated derrick structure about one side ofthe base of the derrick are so arranged that the center of gravity ofthe derrick passes the vertical line through the hinge just before thederrick reaches the upright position. This of course allows the hoistinglines to go slack, and requires the use of snubbing lines in order toprevent the tower from toppling over in the same direction and on theopposite side. This requires a degree of cooperation between thehoisting operator and the man handling the snubbing line which is seldomrealized in practice. In like manner, when it is desired to lower thederrick it is necessary to pull the derrick in the lowering directionpast the dead center position and then catch the derrick on the hoistingequipment which was used to erect the derrick in the irst instance. Theoperation of catching the weight of the derrick as it passes the deadcenter position imposes extreme stresses on the hoisting equipment withthe not too remote possibility that the line will part and allow thederrick to crash to the ground.

Finally, the self-erecting derricks known prior to this inventioninclude auxiliary elevating devices which are used only for the purposeof erecting or lowering the derrick. These devices are so located as tointerfere with the normal use of the derrick in its erected position,making it necessary to assemble the auxiliary structure be- J`fore thederrick is erected, then dismantle that Structure to allow the derrickto be used, then finally reassemble the auxiliary structure in order topermit the derrick to be lowered ready for transporting to a newlocation.

It is therefore an object of this invention to provide a self-erectingtransportable derrick which is particularly adapted for use in therotary drilling of deep wells, and which overcomes the above-noteddisadvantages by incorporating features of construction making thederrick useful for substantially any rotary drilling operation whichcould be performed with a conventional derrick structure.

It is also au object of this invention to provide a selferectingtransportable derrick of the character mentioned in the precedingparagraph which is Prefabricated as a plurality of individual sectionswhich may be individually packed and shipped when the derrick is to besent to a distant location.

It is an additional object of this invention to provide a self-erectingderrick of the character set forth in the preceding paragraph in whichsaid individual sections may be joined together to form a plurality ofsub-assemblies, in which form the derrick may be readily transportedover reasonable distances.

lt is another object of `this invention to provide a selferectingderrick of the character set forth in the preceding paragraph in whichthe individual parts of said subas'semblies are adapted to be folded inside-by-side or traclcway.

* Y Y memos nesting relation with each other to minimize the spaceoccupied by such parts when'the sub-assemblies are transsoconstructed-and arranged with reference to the rest of the derrickstructure as to be used as a part of the derrick structure itself afterthe derrick is erected and ready to beplaced in operation. Y

It is also an object of this invention to provide a derrick-of thecharacter set forth in the preceding paragraph in which vall ofthemechanism lemployed iu erecting the derrick is self-contained within thederricl; structure so as to accompany the derricli when it istransported from one location to ano-therY to thereby ce immediatelyavailable for use in erecting the derrick at the new location.

Itis a-further objectof this invention to provide in a self-erectingderrick of the character described-hereinbefore an erecting mechanismwherein the power for erecting-the derriclt is taken from theconventional draw works suchas is used in the usual drilling operations,

`It is additionally object of this invention to provide a self-erectingderrick of the character hereinbefore mentioned which isarranged toA beerected from a prone to an upright position by rotating the derrickabout pivot axes disposed at the Vbase of the dert-ick, and in which thecenter of gravity of the derrick remains continuously on the same sideof the pivot axis and does not pass the dead center position asischaracteristic of the prior art structures.l Y

Another object of this invention is to provide a selferecting derriclcofthe character hereinbefcre mentioned which includes an automatic latchmechanism cooperating with the erecting mechanism and operating to holdthe derrick in a fixed position when the raising of the derrick hasproceeded to the iinal upright position of the derrick structure tothereby obviate the necessity of employing the-hoisting equipment tohold the derrick nl an erected position until a manual loci; can beapplied.

It is also an object of this invention to provide an automatic latchmechanism of the character set forth in the preceding paragraph whichincludes a manually operated safety lock which may he applied after theVoperation of erected vertical position, and wherein a raising leg isVprovided having one end secured to a fixed pivot and having the otherend bearing against the'underside of the derrickstructure so that aforce applied horizontally to the erecting leg will produce a coupletending to rotate `the erecting leg to a vertical position Vand therebyapply to 4the derrick a couple tending to also rotate the derrick to avertical position7 said fixed pivot for said raising leg being disposedat an elevation lower than said pivot for :the derriclr base.

It is another object of this invention to provide an erecting structureof the character set forth in the preceding paragraph which includes atracliway carried by the derrick Vstructure and which is engaged by themoving end'of the erecting leg to thereby provide for efticientapplication of the erecting force to the derrick structure.

It is also an Vobject of 'this invention to provide an erectingstructure of the character set forth in the preceding paragraph in whichthe traclcway is situated at the upper surface of thehorizontally'disposed derrick and wherein said trackway includes adownwardly inclined portion to thereby minimize the dimensions of theaperture through which the erecting leg extends to meet the It is astill further object of this invention to provide aV self-erectingderrick cf the character set forth hereinbefore which includes aremovable folding pipe rack platform so arranged as to permit the partsthereof to be folded and secured in close abutting relation to eachVother to minimize the space occupied by said platform duringtransportation of the derricii from one drilling site lto another.

Other objects and advantages of this invention will be apparent from aconsideration of the following speciications, read in connection withthe accompanying drawings,

s wherein:

Fig. l is an end elevational View of the preferred embodiment of thisinvention as seen from the pipe rack side;

2 is a side elevation of the structure shown in Fig. l and as viewedfrom the drillers side; i

Fig, 3 is an enlarged elevational view of the base portion of thederrick as seen from the drillers side, and showing the relation betweenthe pivot axis for the dcrrick and the raising leg; I Y

Fig. 4 is a fragmentary diagram illustrating the reeving of the hoistingtackle which connects `the travehng block to the upper end of theraising leg for applying to the raising leg the erecting forces'developedthrough movement of the traveling block;

Fig. 5 is a horizontal sectional view through a portion'of one of themain column members illustrating the detachable connection used to jointhe separable sections from which the mast members of the derricl; areassembled;

Fig. 6 is a fragmentary vertical sectional view of the structure shownin Fig. 5 and illustrating additional details of construction; n Y

Fig. 7 is a diagrammatic view illustrating the mode of operation of theerecting mechanism andillustrating the manner in which the erectingforce applied to the Fig. 8 is a fragmentary perspective viewillustrating the construction of the upper end of the raising leg, andillustrating the apparatus used to connect the raising tackle to theraising leg;

Fig. 9 is a fragmentary longitudinal sectional view taken substantiallyalong the plane 9 9 of Fig. 8 and illustrating the construction of theroller, trunnion, and link mechanism associated with the outer end ofthe raising leg;

Fig. 10 is an elevational view illustrating the construction of thetrunnion used to pivotally secure the lowerV end of the raising leg tothe derrick substructure;

Fig. ll is a side elevational view of an automatic latch mechanism usedto secure the raising leg in the raised position of the derrick, Fig.llY illustrating the positions occupied by the various parts as theraising leg approaches the final erected position;

Fig. l2 is a fragmentary view similar to Fig. l1 but showing thepositions occupied by the parts when the raising leg has been moved toits final position;

Fig. 13 is a fragmentary sectional view taken at right angles to theplanes of Figs. 1l and l2, and further illustrating the cooperativerelation between the upper end of the raising leg and the automaticlatch; p

Fig. 14 is a fragmentary sectional viewtal-:en substantially along theline lli-ld of Fig. 12, and illustrating the construction of a safetylock used to secure the automatic Fig. 17 is a fragmentary perspectiveview illustrating the construction of the upper end of the assembledderriclc structure and showing the manner of attachment of the watertable and crown block assembly to the upper end of the derrick masts;

Fig. 18 is a fragmentary perspective view illustrating the constructionof the folding pipe rack platform;

Fig. 19 is a plan view of the platform shown in Fig. 18;

Fig. 20 is a fragmentary side elevational view with parts shown insection illustrating the construction and operation of a locking andsupport meel for the folding of the ladder in close abut g re- L.on withthe side of the derrick mast when the same is arranged fortransportation;

Fig. 21 is a fragmentary cross sectional view taken sub stantially alongthe line 21--21 of Fig. 2G;

Fig. 22 is a fragmentary perspective view illustrating a modied form ofwater table construction and an alternative means for securing the watertable to the upper end -of the derrick;

Fig. 23 is a vertical sectional view showing a modifie-:l `form `oftrunnion construction for use at the lower end of `the raising leg; and

Fig. 24 is a fragmentary horizontal sectional view v'illustrating theconstruction of a fast line stabilizer.

Referring to the drawings, the preferred embodiment lof the invention isillustrated generally -in Figs. l and 2 :as including a base orsub-structure E-G which may consist of an engine base portion indicatedgenerally at 3l and a derricl. oase portion indicated generally at 32and preferably formed integrally with lthe engine base portion 31 as apart of the integral base structure Si?.

The engine base portion 31 serves to carry the instrumentalities usedduring the operation or" the derrick in the drilling of a deep wellbore, which instrumentalities may include a prime mover 33 for drivingthe slush pumps (not shown) and a prime mover 34 for driving aconventional draw works 35;

The derrick base portion 32 includes a pair of rear derrick basepedest-als 36 and 37 from which rise a pair of masts indicated generallyat 38 and 39 and which together define a derrick tower. When viewed fromthe drillers side of the structure as in Fig. 2, the masts 33 and 39rise vertically, whereas when viewed from the pipe rack side of thestructure as in Fig. l, the masts 32 and 39 converge upwardly and havetheir upper ends interconnected by a water table structure indicatedgenerally at A pair of raising legs 41 and 42 are each piyotallyconnected at their lower ends to front raising leg pedestals 43 and 4-disposed forwardly of the rear pedestais and on the pipe rack side ofthe derrick lioor. The raising legs 41 and 42 extend upwardly andinwardly to each of the masts 38 and 39 to which the upper ends of thelegs 4l and t2 are secured when the mast is erected as shown in Figs. 1and 2.

lt will be understood that the center line of the well lies midwaybetween the masts 3S and 3? as viewed in Fig. l, and lies just to theright of the pedestals 36 and 37 as viewed in Fig. Z-that is, extendingthrough the central portion of the water table d0.

The hoisting mechanism which is used during the drilling of the well tocarry the weight of the drill string and for running the drill stringinto and out of the hole comprises the draw works 35 which provides acable drum (not shown) from which a lfast line 45 extends upwardly andbetween the masts 3S and 39 to pass over one of a plurality of sheavescomprising a crown block assembly d6. The line passes from the crownblock assembly around the sheaves of a traveling block 47 (Fig. 17)encircling the corresponding sheaves of the crown block and thetraveling block a number of times in the conventional fashion. The deadend of the hoisting line is carried from the crown block to the base ofthe derrick structure, and is anchored there in a conventional manner asby being secured to the base pedestal 36.

The assembled and erected derrick also includes a crown or safetyplatform 53, a pipe racking platform 49, an offset platform 5t), andsuitable operating auxiliaries such as a catline Si which passes over acatline sheave 52 and which may be snubbed around a cathead 53 forming apart ot the draw works 35.

The derrick structure thus generally ydescribed is prefabricated as aplurality of individual sections adapted to be transported individuallyto the well site and there joined to make up the complete derrickstructure. The

5% and 39 are separate structures and each comprises a top section 54,an upper intermediate section 55, a middle intermediate section 56, alower intermediate section 57, and a base section 58. The mentionedsections are adapted to be joined to each other in the field and in ther: nner indicated in Figs. 1 and 2 at splicing ions indicated on thedrawings by the reference characters 59, 6d, 6E, and 62, the detail ofthe splicing mechanism used at these locations being shown in Figs. 5and 6 and described in detail hereinafter.

As is best shown in Fig. 17, the upper ends of the masts 33 and 39 areinterconnected through the water table assembly carried by the upperends of the masts. The water table assembly itl comprises a pair ofwater table beams 63 and 64 disposed in parallel spaced relation to eachother and intertied by means of horizontal braces 65 and the crown blockpedestal beam assembly shown at 66. The ends of the beams 63 and 64carry downwardly extending plates 67 which are suitably secured to thebeams 63 and 6d as by welding. The plates 67 dene downwardly projectingtongues 63 which are received between the arms of bifurcated socketmembers 69 secured to the upper ends of the masts 3S and 39, columnmembers 70 and 71 deiining opposite sides of the masts 38 and 39converging inwardly as shown in Fig. 17 to meet at the bifurcated socketmembers 69 to which they are suitably secured as by welding. Alignedbores provided in the arms of the socket members 69 and the tongues 63receive pivot pins 72 serving to pin the water table assembly to theupper ends of the masts.

The interconnection of the upper ends of the masts through the watertable assembly 40 is reinforced by means of prefabricated X-bracemembers indicated generaiiy at 73 in Fig. 17, these members beingsecured to the side faces of the column members and 71 of each of themasts, as is shown in the drawings.

As is best shown in Figs. 15, 16, and 17, each of the masts 3% and 39has a rectangular cross section delined by two pairs of the verticallyextending column members 70, 7i, the column members 70 defining theouter face 0f the mast, and the column members 71 defining the innerface thereof. rl`he column members 79 and 71 are mutually interconnectedby means of a plurality of horizontally disposed, circumferentiallyextending girts 74 spaced at substantially uniform intervals along theheight of the mast. Diagonal braces 75 are extended diagonally acrossthe rectangular openings `deiined by adjacently disposed girts.

As may be seen by reference to Fig. 17, no horizontal girts between theinner face columns 71 are employed in the top mast sections 54. Thesesections accordingly have a rectangular C-shaped cross section disposedwith the open sides or" the C-shapes facing each other to define an openarea through which the traveling block 47 may pass in the upper portionof its travel. To compensate for the loss of stiffness resulting fromthis omission of the horizontal girts, the girts on the other threesides of each mast are made considerably heavier and stronger than arethe corresponding girts employed in the other sections of the structure.

Preferably, but not necessarily, the girts, diagonal braces, and thecolumns are all formed of structural steel angles which may beweatherproofed, either by galvanizing or painting, as may be desired.

As will be made more apparent hereinafter, the pipe racking platform 49is secured to both of the masts 38 and 39 and thus provides across tiebetween the two masts atthe locati'onof the pipe racking platformtending to stillen the structure Vand impart additional rigiditythereto. ln addition to theV pipe racking platform, there is preferablyprovided a removable horizontal strut "le which, when installed,interconnects the columns on the draw works side of the derrick toprovide additional stilening and to serve as a catcher to prevent standsof drill pipe from falling out of the otherwise open side of thederrick. The strut 76 may be pivoted one end and detachably secured atthe other to permit 'the strut to be folded si one Side of one mastduring transportation ofV the derrick to a new location, althoughpreferably the strut 76 is merely Vbolted to'all four of the columns onthe draw works side.

Also, as is fully/'described hereinafter with reference to Fig. 24,'thestrut serves to support fast line 7a for guiding and preventing whippingof ti e fast l 45 during drilling operations.

As is best shown in Fig. l, the lower internediate section S7 and thebase section Sii or" the masts and 39 are tapered in that the inner facecolumns il are incline-l outwardly to meet the vertically extendingouter lace columns 7@ in a trunnion member 77. in addition, the outerface column members 7d and the inner face column members 7l are inclinedtoward each other in the base section S3 so that all four column membersconverge and join at the trunnion member 77. 'E he trunnion member 77 ishingedly connected by a horizontal hinge pin 7S to a swivel member 79which is in turn mounted upon the base pedestal 35 for angular adjustingmovement about a vertical axis. A'plurality or diagonal bracesll.extending outwardly and downwardly toward the draw works from the top ofthe base pedestal 36 and suitably secured to the upper members of thesub-structure 3@ reinforce the base pedestal 36 suiiiciently towithstand any overturning forces thatV may be applied thereto. Thebraces Si) all extend away from the center lineV of the well bore so asto leave a large and unencumbered working space around the rotary table.

The structure used to detachably interconnect the various sections 54-53of the masts 33 and 39 is illustrated in detail in Figs. 5 and 6 withVreference to one of the mast column members 7d, it being understoodthat identical constructions are used at four corners of each of the twomasts. EachV of the 'attachment means includes two pairs of blocks 75and ie, one'of the pairs being situated at the lower end of one sectionand the other pair being situated at the upper end of the section nextbelow. The blocks 75 are positioned on one side face or" the structuralangle column member Y 79, while the blocks T176 are positioned on theother side face of the angle. he blocks are preferably secured to thecolumn members as by welding, and each of the blocks 175 and l75 isprovided with a pair of spaced vertically ydisposed apertures permittingraw bolts 17S andV E79 tobe passed vnwardly through the alignedapertures in thecorrespoading block ef the upper and lower pairs, thedraw bolts EWS and 79 being used to 'draw the two sections into secureabutting engagernent with each other. it has been found in practice thatthis form ci attachment permits ready alignment of the column membersand allows said members to be secured Yto each other with `a minimumexpenditure of time and eort.

Horizontally extending bolts l?? passed through suitable apertures inthe blocks 175 and 17e serve to secure the girts and braces to the mastcolumns. By this means, a more compact framing obtained at the splicelocation and eccentric bracing is avoided.

The erecting mechanism which isV employed to raise the derrick from aninitial prone pesiticfiV as represented diagrammatically by the solidlines in Fig. 7, to an erect position, as represented by the erectVdotted line view in Fig. 7, comprises the raising legs di and fl-2 incon operation Ywith the masts 3S andV 39 'and thedenickbase CLI portion;tegether with; the. .tactile system vlsihis Shown in Fig.V 4 for'developing the. erecting force. When the 'derrick is'in theproneposition, the raising legs. .41 extend outwardly from their lower pivots43 and intothe contines of the masts 38 and 39 throughgsuit'able Aopen-Vthe erecting operation) a sling yoke 85. Theslingyoke 85 has pivotallyattached thereto a pair of cable sockets S6 and 87 connected to theYends of the wire lines or cables and 39 associated respectively withVthe masts 3b and 39. The cable 88 extends downwardly and outwardly fromthe hook 84 to pass around aswlvel block 913 secured as by means of ananchor pin 91 to Ythe nion meinber77. From the swivel block 9i) therline98 passes upwardly within the outline of ythe mast 38 and around anupper raising blocli'92. The upper raising block is connected Vby meansof a cross head yoke assembly indicated generally byithe referencecharacter 93, and described in more detail hereinaftentothe outer end ofthe raising leg'41. After passing around the upper raising blocl: 92,the wire line 88 ypasses down- .'ardly within the contines of the mast38 and around an intermediate raising block 94 Vwhich is secured as bymeans of a suitable anchor link 95 to the aforementloned anchor pin 91.After passing around the middie raising blocl; 94, the line 88 againpasses upwardly within the interior of the mast 38 and is connected tothe frame of the upper raising block 92. The wire line S9 connected tothe yoke .SS'andassociated with the other mast 39 is rigged in aprecisely similar manner.

A turnbuckle 96 may be connected .between the frame of the block 9,2 andthe end of theV line 88 as ameans Y the masts 38 and 39 when both lines38 and S9Yare taut.

Referring now to Figs. 2, 4, and 7, it will be seen that by winding thefast line 45 of the main hoist upon the hoisting drum of the draw works35, the traveling block i7 will be moved outwardly toward the crownblock when the mast is in the prone. position. This will cause the lineVS8 to move outwardly as is represented in solid lines in Fig. 7. Thereeving of this line over the block 9i), 92, and 94 constitutes a tacklesystem interconnecting the outer end of the raising leg 41 with thelower end of the mast as at trunnion member 77. The tackle system thusapplies a tension force between the outer end of the raising leg 41 andthel lower end of the mast along a line which is substantiallyhorizontal and which passes above the lower pivot 43 for the raisingleg. 41, thus producing a couple tending to rotate the raising leg 41 in'a counterclockwise direction as viewed in Fig. 7. Obviously,the tacklesystems may include a greater or smaller number of line-parts .extendingbetweenV the pulleys 92 and 94 depending upon the mechanical advantagedesired.

The cross head roller assembly at the outer end of the raising leg 41bears 'against the track S2 and serves to resolve the aforementionedrotative couple into an upwardly directed force applied to the mast 38at the point of engagement of the roller assembly .with thetrack 82.This upward force acting at a considerable distance from the pivot 7dcauses the mast 38 to be rotated in a counterclocltwise direction aboutthat pivot.

The erecting rotation of thefinast 38 is accompanied 9 neous raisingforce. The dotted line positions shown in Fig. 7 represent the relativeorientations of the masts and the raising legs during the motion fromthe initial prone position to the finally erected position, such finallyerected position being also represented in Fig. 3.

The raising legs 41 and 42 are preferably made adjustA able in length byany suitable adjustment means such 'as that represented at 97 in Fig. 3to provide for adjusting the verticality of the masts when the partsoccupy their fully erected positions.

Certain types of draw works provide a hydrodynamic brake immediately infront of the hoisting drum for the fast line 45. The fast line 45extends horizontally away from the derrick base when the derrick is in aprone position, and in order to prevent interference between the fastline in this position and the hydrodynamic brake, the draw works ispreferably provided with an elevated idler roller 98 which serves toelevate the fast line 45 Aa distance suflicient to clear theaforementioned brake.

As is best shown in Figs. 8 through 14, the raising legs 41 and 42 eachcomprise a pair of channel members 10i) disposed with their open sidesfacing and interconnected at frequent intervals along their length bylateral stiifeners 101. rihe lower ends of the channels 100 receive andare suitably secured as by welding to a lower end terminal 102 forming apart of the raising leg pivot assembly 43 hereinbefore mentioned. Theterminal member 102 is bifurcated to receive between the arms thereof atrunnion block 103 to which the terminal member 102 is pivotallyattached as by means of a transverse pivot pin 104. The trunnion block163 is in turn pivotally supported, as by means of a pivot pin 105,between the upstanding arms 166 and 107 of a base shoe 108. The baseshoe 108 includes ange portions 109 adapted to be secured as by bolts,welding, or otherwise to the raising leg pedestal.

At their outer ends the channels 100 are secured to a box-like structure110 fabricated as by welding from upper and lower plates 111 and 112 andside plates 113. Within the box so defined there is positioned atrunnion block 114 carrying vertically extending pintles 115 passingthrough suitable apertures in the upper and lower plates 111 and 112 andserving to journal the trunnion block 114 for limited angular rotationabout the vertical axis of the pintles 115. The trunnion block 114 isbored as indicated at 116 to receive a cross shaft 117 upon the outerends of which are rotatably mounted suitable rollers 118. The rollers118 are preferably fitted with' bushing or antifriction bearings 119 andare axially held between a shoulder 129 on the cross shaft 117 and alock ring 121 received in a suitable annular groove formed in theoutermost end of said shaft.

A pair of cross head links 122 and 123 are bored to pass over the shaft117 at opposite sides of the box-like structure 110. ln those positionsthe links 123 are axially restrained between a shoulder 124 formed onthe shaft 117 and a spring snap ring 125 received in a suitable annulargroove formed in said shaft. rlhe outer ends of the links 122 and 123are provided with pivot shackles 126 and 127 which are pivotally securedto a yoke member 128 as by pivot pins 129 and 130. The yoke 128 ispivotally joined as by means of a pivot 131, line 132, and pivot 133 tothe frame of the upper raising block 92. The cross head links 122 and123, together with their attachment means just described, thus serve toapply directly to the cross shaft 117 the tension forces which areexerted by the raising tackle in response to movement of the travelingblock.

The rollers 11S are adapted to move along the trackway 82 hereinbeforedescribed. As more clearly appears in Figs. S, l5, and 16, the trackway82 comprises a pair of tracks indicated generally by the referencecharacters 134 and 135, and associated respectively with one or theother of the rollers 118. Each of the trackways 134 and 135 comprises anupper channel member 136 and a lower channel member 137. The upperchannel member 136 isse- 75 cured to the face of an l-beam 138 which issuitably se-f cured as by welding to the structure of the mast 38 or 39,as the case may be. The channel 137 is turned on its side' and alsosecured to the structure of the mast. This channel serves as a catcherto carry the upper end of the raising ieg 41 when the same is notapplying a lifting force to the mast. i

The trackways 134 and 135 extend vertically and parallel to the lengthof the mast 38 along the draw works side thereof for substantiallyone-half of their length, the' lower portion of the trackways beinginclined toward the pipe rack side of the derrick and terminating nearthe pipe rack face of the mast. By making the tracks 134 and 135 of twoangularly disposed portions as described, the window 81 through whichthe raising leg 41 extends may have a minimum vertical dimension whichis much less than would be the case were the trackways 134 and 135extended vertically for their entire length.

When the mast is raised to its erected position, the rollers 118 havebeen caused to move downwardly along the trackways 134 and 135 to thelower ends thereof. At this location on each of the masts 33 and 39there are provided automatic latching devices which serve to secure eachof the cross shafts 117 to the associated mast at that location so thatthe erecting force may be released without the yderrick returning to itsoriginal prone position. The latching mechanism is duplicated for eachend of the cross shaft 117, and the construction of one is illustratedin Figs. ll through 14.

As may be seen from an inspection of the enumerated ligures, eachlatching mechanism comprises a frame formed of spaced parallel plates140 and 141 disposed in vertical planes parallel to the inside andoutside faces of the mast 38. These plates are secured to supportingmembers 142 and 143, welded or otherwise suitably attached to the mastcolumns 76 and 71. At the location of the latching mechanism, as may Deseen in Fig. l5, the usual horizontal girts 74 are replaced by heavybrace members 144 serving to further support and stiften the latch frame140--141 The plates 14d and 141 are shaped as shown in Figs. ll and l2to define aligned semi-circular notches 145 which are so positioned atthe ends of the trackways 134 and 135 as to receive a slightly reduceddiameter portion 146 of the cross shaft 117 when the raising leg 41 ismoved to the limit of its travel, the shaft portion 146 being disposedbetween the roller 118 and the cross head links 122 and 123.

Between the plates 149 and 141 there is rotatably supported a pivotedlatch member 147, a pivot pin 148 passing through the plates 141B and141 and through the member 147 providing a rotational mounting of thelatch member. The latch member 147 is shaped as shown in Figs. 11 andl2, and includes an actuating projection 149 initially dis-- posedwithin the notch 145 in a position to be engaged` by the cross shaftportion 146 as that portion is moved` into seating relation in the notch145. The engagement: of the shaft portion 146 with the operatingprojection 149 forces a clockwise rotation of the latch member 147 whichserves to move it from the position shown in Fig. ll to the positionshown in Fig. l2, in which latter position the shaft portion 146 isconfined within the notch 145 by a portion of the latch member 147 whichldefines a surface 158-151 extended in such a direction as to liesubstantially at right angles to the direction of movement of the shaft146.

The side of the latch member 147 opposite the operating projection 149is formed with three ratchet teeth 152, 153, and 154 which arepositioned to be engaged in three separate angular positions of themember 147 by a pawl 155. rl`he pawl 155 is disposed between the plates140 and 141 and is mounted for axial sliding movement into and out ofengagement with the notches defined by the ratchet teeth 152-154. Thepawl 155 is spring urged inwardly as by a compression spring 156, :andis provided Y assi-,ros

with a chain 157 or similar exible tension means which extends to theiioor of the derrick to permit the pawl 155 to be withdrawn fromengagement with the latch member 147 by a Workman on the derrick licor.

The ratchet tooth 152 is disposed in a position to hold the 'latchmember 147 in an initial position such as is shown in Fig. ll in whichthe operating projection 149 Y is disposed in the path of movement ofthe cross shaft portion 146. The ratchet tooth 154 is positioned toholdl the 1latch member 147 in the latched position Vwhich isillustrated in `Eig. l2. The ratchet tooth 1:3 is disposed substantiallymidway between the teeth 152 and 154 and serves as a safety measure toprevent counterclockwise rotation of the latch member 147 in the eventthe pawl 155` fails to completely engage the ratchet tooth 154.Furthermore, the tooth 153 produces an audible click when it passes thepawl 155 during the movement of the cross shaft 117 toits final positionseated within thek notch 154, and thus serves to indicate to the Workmanerecting the derrick'that the linal position of the structure is beingclosely approached. Y

As is best seen in Figs. ll and 14, the frame plates 14) and 1411Vinclude upwardly extending portions 158 through which are extendedaligned rectangular apertures 159. VThe latch membertd includes atailpiece 161i de- .tining a piane surface 161 disposed in such locationthat rotation of the member 147 to the latched position shown in Fig. l2moves the surface 161 to a position coplanar with the lower surface 162of the rectangular opening 159. As will be described in the ensuingparagraphs, Y

wedge members driven or forced into the rectangular apertures 159 engagethe surface 161 so as to positively lock the latch member 147 againstcounterclockwise movement to a position which would releasethe'crossshaft 117.

Y As is shown in Fig. l4, the wedging devices for providing a safetylock such as has just been described constitutes a singleinstrumentality adapted to simultaneously Vlock the latch members1-7 ofboth of the automatic latching devices. This instrumentality includes apair of tapered wedge members 163 and 164, one foreach of the latchmembers 1457. rl`he wedge members 163 and 164 are provided with arectangular cross section to allow them to be readily but non-rotatablyreceived within the rectangular openings 159. The taper of the members163 and 164 is so arranged as to provide the desired wedging and lockingaction upon movement of these members outwardly away from each other asshown in Fig. 14.

The wedge member 163 is bored to receive a jack-g shaft 165 which isfreely rotatable within the bore in the wedge member 163. The wedgemember 163 is held against axial movement relative to the jackshaft 165byV means Vof an inner collar 166 which is secured to the shaft as bymeans of a pin or like device. A nut 167 or like member or" polygonalcross Ysection is similarly xcd on the outer end of the jackshaft 165 soas to contine the wedge member 163 between the nut 167 and the collar166.

The right-hand end of the jackshaft 165 is threaded as shown at 163, andthreadedl'y engages a threaded opening 169 provided in the wedge member164. it will be seen that rotation the jackshaft 155 will thus cause theedge members'163V and 1641 to move toward and away from each otherbetween positions such as are Valternatively shown in dotted and solidlines in Fig. 14. Such rotation of the jackshaft 165 may be effectedmanually as by means of a socket wrench 17? applied Vto the nut 167.

While the derrick structure is beingV shipped to the erection site,thelock-jack assembly just described is carried in a suitable b x (notshown) secured to the side of the derrick structure near the intendedplace of use. To prevent the dropping or other loss of the lock-jackassembly, the same .is preferably secured to. the 'derrickmoved topositions' asV closely adjacent each other as theV length ofthe thread168 will: permit, as isY represented by the dotted line showing in Fig.14.

YWhen the derrick has been Ymoved tothe fully erected position so as torotatethe latch member 147 to the poa sition shown in Fig. Vl2', theloclojack assembly is then applied as a safety lock. This isaccomplished by first passing the exposed threaded end of the jackshaft165Y through the rectangular openings in one'pair of the frame members140 and 141 as is represented by the dotted line 'showing in Fig. 14with: respect tothe right-hand frame members. This positions theV nut167 inwardly of the frame 141 of the left-hand automatic latching mecha#nism so as to permit the lock-jack assembly to be angularly moved intoalignment with the rectangular aperj tures therein and then slid axiallyto the left asVv viewed in Fig.,14 to move thewedge member 163 to theposition shown insolid lines in that gure.

Thereafter, rotation ofthe nut 167 through the use of the wrench 17Bwill cause the wedge member 164 to move outwardly relative to the wedgemember 163 andV so into the Vrighthand rectangular opening. When 'bothVwedging members 163V and 164 are in place, additional force applied tothe wrench 170 will wedge these members-in their respective aperturesand provide a positive safety lock which willprevent inadvertentmovement of both of the latch members 147 toward their released poesitions. Y

When it is desired to lower the derrick as for transporting to a newlocation, the lock-jack assemblies are` causes the cross shaft 117 tomove upwardly asviewed in l This movement `of the cross shaftrroiiigs.l1 and l2. tates the latch members 147 to their init-iai positions asshown in Fig. ll. The automatic latching mechanism for the raising legs41 and 42 thus beingreleased, the derrick may be lowered to a proneposition by continuing to pay cable olf of the Winding drum ofthe drawWorks.

When. the Vderrick finally reaches the `prone position as shown in solidlines in Fig..7, the rollers 118 engage af fixed stopmembcr9?. Theiixedstop member 99' is iirmly secured vto the 1mast38 Aat the outer end'ofthe trackway 82 and in. aposition to prevent further outward relativemovementof the upper end of the raising leg 41When the mast 38: reachesYa `substantially horizontal position.

The stop 99 Vthus cooperates with the raising leg 41 to limit theamount'ofclockwise movement the mast may make inf-approaching the proneposition to thereby limit to adeiinite minimum value Vthe lever armlength of the erecting coupled. It will be appreciated that thisleverarmfresults from t e pivot 78 beinor disposed a substantial distanceabovelthepivot '43, and that the length of this lever arm would bereduced by clockwise rotation of the mast 38 beyond the described proneposition. When the raising leg-41 engages the stop 99, the hoistingtackle goes slacl;, permitting the hook on the Vtraveling block tobeidisengagedlfrom theyoke 8S. Y

When the-derrickis rst erected and is then to be put into normal use,'itis ofcourse necessary to disengage the traveling block 84 from the yoke5. In the erected posi# Y tionfof the derrick,fthe yoke 85 has beenmoved upwardly to a Pnt near thefto'p-of thederrick, as maybe seen byreference tof'F-ig. l1. `Todlsengage the raising sling-cornprising theyoke and cables 88 and 89, the traveling block is lowered to theplatform 49 at which point a workman may fasten one end of a slingstowage line 51a to the yoke 8S. The sling stowage line extends upwardlyto the water table where it passes over a sheave 52a, the free end ofthe sling stowage line falling to the derrick floor where it may bepulled, either manually or by passing the same around the cathead S3 toutilize the power of the draw works.

Upon pulling the free end of the sling stowage line, the raising slingis again elevated to a position such as that shown in Fig. l, but byreason of the lateral displacement of the sheave over which the slingstowage line passes (see Fig. 2), the raising sling is Icaused to lieclosely adjacent the draw works side of the derrick and in closerelationship to the inside faces of the masts 38 and 39. When theraising sling has been elevated and positioned as described, the lowerend of the sling raising line may be tied olf to the bottom of thederrick in any suitable fashion. To prevent inadvertent interferencebetween the raising sling and the normal up-and-down movements of thetraveling block, the raising sling lines 88 and 89 may be temporarilysecured to the column members of the masts by suitable hand lashing.

As may be seen at 1813 in Fig. 2, the derrick structure is provided witha ladder extending from the derrick oor to the oor of the safetyplatform situated at the crown block 46. The ladder is made up inindividual sections ycorresponding in length to the length of theprefabricated mast sections 541-58, and are secured to these sections ina manner to be described.

Each ladder comprises a pair of longitudinal members 181 and 182 betweenwhich are extended at suitable intervals rung members 183. As may bestbe seen in Fig. 1, during the normal use of the derrick structure theladder must be spaced from the side face of the derrick a distancesufficient to permit ample toe room for workmen ascend.- ing anddescending the ladder. However, when the derrick is knocked down fortransport to a new location it is desired to save space by moving theladder 180 into close abutting relation with the side of the derrick. Insuch a position, the ladder is protected against damage during handlingand moving.

A folding structure for mounting the ladder is illustrated in Figs. 2Oand 2l as comprising a plurality of links 184 pivotally secured at oneend as by pivots 185 to the structural members of the mast and pivotallysecured at the other end as by pivots 186 to the longitudinal laddermembers 181 and 182. This mounting permits the ladder to be hingedlymoved between the two positions shown respectively by the dotted linesand solid lines in Fig. 20.

Clockwise movement of the links 184 is arrested in the solid lineposition shown in Fig. 2O by the engagement of the ladder members181-183 with the side panel of the mast. To limit counterclockwisemovement of the links 184 to the position shown in dotted lines in Fig.20, the lower pivot preferably engages a clip member 187 which issuitably secured to one of the horizontal girts 74. When the link 184 isrotated to the position shown in dotted lines in Fig. 20, theundersurface of the link engages the upper surface of the girt 74 whichthen prevents further downward movement of the link.

Means are provided for locking the ladder in the folded position asshown in full lines in Fig. 20. This means comprises a bolt 188 which ispassed through a suitable transversely extending aperture formed in alug 189 welded or otherwise suitably formed on the outside surface ofthe links 184. The upper end of the bolt 188 is threaded to receive awing nut or thumb nut 190, and the lower end of the bolt is headed asshown at 191. At suitable locations on the longitudinal ladder members181 and 182 there are provided clip members 192 which comprise a pair ofoutwardly extending ears 193 defining therebetween a channel 194 forreceiving the lower end of the shank of the bolt 188, the head 191 beingposi- 14 tioned below andV engaging the ears 193. Such a relationbetween the bolt and the clip 192 is shown in solid lines in Fig. 20.

When the bolt is engaged with the clip 192 in the manner described, thethumb nut may be tightened to force relative rotation between the link184 and the longitudinal ladder member 182. This forced rotation resultsin pulling the ladder into firm abutting engagement with the side faceof the mast and serves to hold the ladder firmly in the folded position.

ln transporting the derrick, it is desirable to leave the travelingblock and crown block reeved, but it is necessary to hold the travelingblock so as to prevent tangling or snarling of the traveling block line.Accordingly, the upper section 54 of the mast 39 is preferably providedwith a plurality of longitudinally extending auxiliary members 195 whichare secured to the girts and braces on the three outer surfaces of themast 39. The auxiliary members 195 thus define a cradle within which thetraveling block may be confined and held as by hand lashing or othersuitable attachment.

ln the interests of saving space when the derrick is to be transportedfrom one location to another, the working platform 49 is detachablysecured to the derrick structure, and is so constructed as to permit thedet-ached platform assembly to be folded into a relatively small compactpackage. The construction of the platform 49 is illustrated in detail inFigs. 18 and 19.

The base or working iioor of the platform 49 is de` fined by an outerframe member 268 of tubular form which is connected as by channelmembers 201 and 202 to a pair of inner frame members 263 and 284, theinner frame members 283 and 204 being coaxially disposed and extendingacross the pipe rack sides of the respective masts 38 and 39 to whichthe frame members 283 and 2114 are detachably secured as by bolts 205and clips 206. The frame members 293 and 284 are spaced apart axially toleave a gap therebetween through which the upper ends of stands of drillpipe resting on the derrick floor may be moved to bring them into thearea defined by the outline of the platform 49. The members 203 and 204are preferably of tubular form and have telescopically received thereinsliding pins 207 which may be slid toward each other so as to close theaforementioned gap.

The floor of the platform comprises suitable metal plates resting uponand secured to the base framework just described. These plates, whichare identified in Fig. 19 by the reference characters 2118, 269, 21),and 211, define a C-shaped walkway around the outer perimeter of theplatform area. The floor structure just described is preferably bracedby means of a pair of inclined braces 212, secured at one end to theplatform frame members 282 and secured at the other end as by means ofbolts 213 and clips 214 to the column members of each of the masts.

The platform working area is completely enclosed by a safety railingwhich is made up of a center panel indicated generally at 215. The panel215 is supported by posts 216, 217, and 218, which are in turn attachedto the tubular base frame member 299 as by means of socket members 219.The members 21Sl are rotatable relative to the frame member 280 so as topermit the rear railing panel 21.5 to be folded down fiat against theiioor of the platform.

End panels 2211 and 221 include inner posts 222, the lower ends of whichmerely rest upon the frame members 2113, and outer posts 222 which areso secured to the posts 216 and 218 by clips 223 as to permit rotationof the posts 222 relative to the posts 216. This perm-its the end panels228 and 221 to be folded inwardly against the outer panel 215 and inoverlapping relation thereto and in relation to each other before thefolded railing assembly is folded down against the floor of the platformitself.

The platform floor also includes a center catwalk portion 225. Thisportion is hingedly secured at its outer assai-os VKnd as by means ofhinges 226 to the horizontal frame member 2% toperrnit the catwalk to befolded up Yagainst the outer railing panel H5. The catwalk may be' heldin such folded position by means of Va latch member 227 adapted toengage a suitable latch aperture 228`provided w in the catwalk member225. In its unlatched and lowered position as shown in Figs. i8 and 19,the 'catwalk 225 rests upon' a` horizontally extending frame member22,9.

To facilitate the racking of stands of drill'pipe a pair ofracking rakes230 and 231 are provided, these rakes each comprising a plurality ofhorizontally extending finger members suitably secured to the'frameworkof the platform. lt will be understood that stands of drillpipc may beslipped between the lingers of the rake and so held in a regularlyarranged order.

lt will be seen that the working platform construction just describedprovides ample working space and all of the facilities for racking theupper ends of stands of drill pipe, Vwhile at the same time beingreadily detachable from the derric'k structure and foldable into a smallpackage to facilitate transportationV thereof. v

ln Fig'.A 22 therek isshown an alternative construction for securing thewater table assembly 4-l'to the upper end of the derrick. in thisconstruction the socket members 69 are omitted and replaced by gussetplates 235 which are secured, preferably by welding, to the upper endsof the column members 7i) and 7i. A pair of pipe struts 236 are extendedhorizontally beneath the water table beams 63 and 64, and arepermanently secured to theV upper ends of the masts and 39V' as by beingwelded to the ends of the column members 7l) and 71 and to the gussetplates 235.V Diagonal braces 237 are extended between the pipe strut 236and the column members 78 and 7l to increase the rigidity ofthe'stiucture. Saddle blocks 23S, welded in appropriate location to theunderside of the water table beams 63 and 64, provide curved .bearingsurfaces for engaging the upper cylindrical surface of the pipe-struts236 at each end thereof. Shear blocks 239 may be welded to the uppersurface of the pipe struts 236 to hold the water table beams 63 and 64against endwise movement relative to the struts 236.

The water table beams *'63 and 64 are clamped to the struts 236 by meansof U-bolts 246 which passthrough suitable apertures in the undersideflanges of the water table beams, and are held in place as by means ofnuts 2471. By tightening the nuts 241, the water table beams 64 areiirmly and securely clamped to the pipe struts When it is desired topivotally move the masts 3S and 39 toward each other as describedhereinbeforc, the U- bolts 249 are loosened to permit the pipe struts236 to rotate relative to the water table beams 63 and 64.

Thealternative construction described with reference kto Fig. 22 issomewhat less expensive to construct than that shown in Fig. 17, andprovides an adequately strong attachment of the water table structuretothe upper end of the derrick.

. ln Pig. 23 there is illustrated a modified form of raisingV leg pivotassembly 43 which employs Va self-aligning bushing instead of thetrunnion construction heretofore described with reference to Fig. 1G. Asis shown in Fig.v

23, the channel members still defining the raising legal may be securedto an annular bearing block 245. The

Vbearing block 2&5 is provided with a large central aperture Y bers.nThe inner m mber 248 is bored to receive the pivot pin lili, and may being arms and lo of .spacer sleeves 256.

held eutrally between the opstand- 7 of the base shoe los as by meansthe anis of thepivot 19,5, while at the sameV time permittned to enjoypivotal-movement in the plane of thev figure,v this latter pivotalmovement lbeing-permitted by the self-aligning bushing 247, 243 whichpermits the member '247 to rotate about the spherical surface 249.

The aforementioned alternative construction of the removable back strut776 and the construction of the fast line stabilizer 76a is illustratedin Fig. 24. As is shown therein-the strut 76 may comprise a suitablelength of structural steel l-beam which is secured to the draw worksfaces of each of the masts 33 and 39 as by being bolted to thecolumn'members 7i? and 71 thereof, as -is indicated at 255. This form ofattachment allows the strut 76 to be shipped separately and attached tothe masts 38 and 39 during field assembly while the derrick is in aprone position. 4 Y

The fast line stabilizer 76a preferably comprises a framework defined bya pair of angle members 256' and- 257 which are held in parallel spacedrelation to each other by a transverse angle 258 suitably secured as bywelding to the Vangles 256 and 257. The-frame thus defined rests'on theupper surface of the anges of the back strut 76and may be iirmly aihxedthereto by Ymeans of four J-bolts 259 which pass downwardly along theouter surfaces of the iianges and hook under the lower edges thereof.Nuts applied to the upper ends of the J-bolts permit the .frame to beclamped securely to the strut 76. Preferably, the angle members 256 and257 are provided with a plurality of holes spaced along their lengthsfor receiving the J-bolts259in a plurality of positions of the framerelative to the strut 76.

Between the voutwardly extending arms of the angles 256 and 257 thereare mounted a pair of rollers 260, 262i. These rollersfare journaled forfree rotation as by means of pintles 262 extended through suitablebearing apertures formed in the upstanding anges ofthe angles 256 and257 L The rollers 26C-, 261 are spaced apart to define between theiradjacently disposed cylindrical surfaces aV small space for receivingthe fast line 45.

' The fast line stabilizer 76a is thus adapted to be Vati tached to theassembled derrick at the same time that the which is particularlyadapted for shipmentv and erectionY at the drilling site. It willalsobe'seen that the device is so constructed as to permit the-derrickto `be readily transported from one drillingY location to another. lnthis connection it should be observed that for relatively shortdistances the' entireV upper section of the derrick may be handled'as aunit consisting of the toprsections 54, to.- gether with the water table40 and crown block assembly 46 attached thereto. sub-assembly in thisfashion, the' X-brace member 73` is disconnected from one of the masts.This permits the two mast sections' to be pivotally moved about the pins72 into abutting relation with each other, where they may be secured bysuitable means and in which relative positions they occupy a minimum ofspace.

Attention is also directed tothe fact'that the erecting means comprisingtheraising legs-41 andV 42 operate` as structural elements of thederrick during the normal use of the derrick, and are self-containedwithin their Vrespective masts during the time that the derrick is beingtransported from one location to another. .An outstanding characteristicof the construction described herein is in the substantially completeelimination of 'auxiliary mechanisms for raising and lowering thederrick. Instead, the members used in the structure of the operatingderrick are employed as Athe raising means without the use of auxiliaryA-frames, gin poles or like devices. An im- When 'the device is shippedas aV 17 portant feature in connection with the use of the raising legs41 and 42 for the erection of the derrick resides in positioning thederrick base pivots above the raising leg pivots so as to provide asubstantial lever arm for translating the tension forces developed bythe raising sling into a couple tending to rotate the raising legs.

It should also be noted that when the derrick is erected, the raisinglegs extend angularly downward and away from the pipe rack side of thederrick to deine a high inverted V window to facilitate drawing in pipeand like equipment from the side of the derrick.

The difference in elevation between the derrick base pivots and theraising leg pivots just mentioned is obtained by mounting the derrickbase pivots on the top of the derrick base pedestals. Attention isdirected to the fact that the bracing for these pedestals extends awayfrom the derrick oor space so as to obviate any interference with thedrilling operations which are conducted within that oor space. Alsoworthy of note is the fact that the entire raising tackle is housedwithin the coniines of the masts with which they are associated, thusmaterially facilitating the transportation of the equipment from onewell site to another.

The structure described has adequate strength and rigidity to permit itsuse in the drilling of deep wells. By reason of such strength andrigidity, and because the erected derrick stands upon a base of amplesize, no guys are required as is the case with the self-erectingderricks known prior to this invention.

Finally it is desired to call attention to the automatic latch andsafety lock mechanism for holding the derrick in its erected position,and also to the fact that in moving from the prone position to theerected position the derrick does not cross the top dead centerposition, thus obviating many of the disadvantageous features of theprior constructions.

In addition to its use in drilling wells, the mast of this invention canhave other uses including use as a staging device for launching rockets.In such use, suitable work platforms can be distributed along the mastsheight so that when the mast is erected, and a rocket placed adjacentthereto, workmen can easily service the rocket from the work platforms.When the rocket is ready to be launched, the mast can be lowered and, ifdesired, moved away from the rocket.

While the preferred embodiment of this invention has been illustratedand described herein, the invention is not to be limited to the detailsof construction shown and described, except as dened in the appendedclaims.

We claim:

l. In a self-erecting derrick: a tower pivoted at its base for movementto an erect position; two unitary and structurally independent liftingmembers movable simultaneously longitudinally of said tower alongpredetermined paths to move said tower -to said erect position; a pairof latches at the ends of said paths for engaging and holding saidmembers and including locking projections movable past rectangularapertures in latch base plates and auto-operated releasable means forholding said locking projections in latching position; and a manuallyoperable supplementary safety lock comprising a pair of rectangularwedges for insertion into said apertures to hold said projectionsagainst movement past said apertures, said wedges each having alongitudinal bore therethrough, an operating shaft extending throughsaid bores, cooperating screw threads on said shaft and in the bore ofat least one of said wedges for producing relative axial movement ofsaid wedges upon rotation of said shaft relative to said wedge, saidscrew threads having a length suflicient to move said wedges from aninitial position in which the distance between the outer ends of saidwedges is substantially less than the distance between said apertures toa locked position in which said wedges are separated a distance suicientto lock said wedges in said apertures.

2. In a self-erecting derrick, the combination of a der'- rick towerincluding an upwardly converging pair of legs; a derrick base forsupporting said tower; a lirst pair of pivot means securing said towerlegs to said base for rotation of said tower legs about a horizontalaxis between an erect position and a prone position extending said towerhorizontally in a forward direction from said pivot means; two unitaryand structurally independent raising legs; a pair of universal pivotmeans on said base in front of said first pair of pivot means pivotallysecuring one end of each of said raising legs to said base forindependent compound pivotal movement of each of said raising legs abouta horizontal axis between positions corresponding to said prone anderect positions of said tower; means carried by the other ends or" eachof said raising legs, respectively, engaging said tower legs formovement therealong to apply to said tower an erecting force in responseto rotation of said raising legs about said second pair of pivot means;and power means for rotating both of said raising legs in unison.

3. in a self-erecting derrick, the combination of: a derrick towerincluding -an upwardly converging pair of legs; a derrick base forsupporting said tower; ka first pair of pivot means securing said towerlegs to said base for rotation of said tower legs about a horizontalaxis between an erect position and a prone position extending said towerhorizontally in a "forward direction "from said pivot means; two unitaryand ystructurally independent raising Ilegs; a pair of universal pivotmeans on said base in front of -said first pair `off pivot meanspivotally securing one end of each of said raising legs to said base forindependent compound pivotal movement of each of said raising legs withrespect to a horizontal axis between positions corresponding to saidprone and erect positions of said tower, said universal pivot meansbeing disposed at `a lower elevation than said tirst pair `of pivotmeans; means carried by the other ends of each of said raisin-g legs,respectively, `engaging said tower legs and movable therealong forapplying to said tower an erecting force in response to rotation of saidraising legs about `said second pair of pivot means; traction meansconnected at one end to a point near said lirst pivot means and at theother to said other ends of both of said raising legs and operable toapply to said other ends a substantially horizontally rearwardlydirected force for rotating both of said raising legs in unison; fandpower means for operating said traction means.

4. ln a self-erecting derrick, the combination of: a

Y der-rick tower including a pair of legs each of which has front andrear structural members extending longitudinally thereof; a derrick basefor supporting said tower; a iirst pair of pivot means securing saidtower legs to said base for rotation of said tower legs about ahorizontal axis between an erect position and -a prone positionextending said tower horizontally in a forward direction from said pivotmeans; a pair of raising legs; a second pair of pivot means on said basein front of said iirst pair of pivot means pivotally securing one endyof each of said raising legs to said base for pivotal movement about ahorizontal axis between positions corresponding to said prone and erectpositions of said tower; a pair of track means respectively securedwithin said tower legs to extend longitudinally thereof with at leastlan upper portion of each track means being disposed laterally betweensaid front and rear structural members, said track means each having anabutment adjacent each of its ends; means carried by the other end ofeach of said raising legs engaging the corresponding one of said trackmeans and constrained to ymovement therealong between said abutments forapplying to said tower Aan erecting force in response to rotation ofsaid raising legs about said second pair of pivot means; and power meansfor so rotating ssaid raising legs.

5. In a self-erecting derrick, the combination of: a derrick towerincluding a pair of legs having `front and 19 rearV faces; a der-rick;base forV supportingr said tower; a V rstfpair of pivot means securingsaid tower legs to said base for rotation of said tower legs aboutahorizontal axis between an erect position and a prone position; a pairof raising legs; a second pair of pivot meansV on said base in front ofsaid first pair of pivot means pivotally securing one end of each ofsaid raising legs to said base for pivotal movement about a horizontalaxis be- Vtween positions corresponding to said prone and erectpositions of said tower; a-pair -of -track means, one for each of saidraising legs, secured to said tower and extending longitudinallythereof, each of said track means including an upper portion adjacentsaid rear face extending downwardly along said rear face toward saidfirst pivot means, and including a lower `angulary-disposed portionextending from the lower'end of said upper portion downwardly andforwardly and terminating adjacent said front face; track engaging meanscarried by the Vother end of each of said raising legs for engaging thecorresponding one of'said track means and applying to said tower anerecting force in' response to rotation of said raising legs aboutsaid'secondrpair yof pivot means; and power means for so rotating saidraising legs.

6. in la self-erecting derrick, the combination of: a horizontal base; apair of hollow columnar legs joined at their distalends and spaced apartat their proximal ends to form when erect, an inverted V-.shaped tower;a .pair of axialrly aligned pivots connecting said proximal ends to saidbase lfor swinging movement of said tower between said erect positionand a prone position extending forwardly from said pivots; two unitaryand structurally independent raising legs, each having a proximal endthereof universally pivoted on said base at a point forward of one ofsaid tower leg pivots, each being disposed within a respective oneof-said tower legs when the same are in said prone position, and eachraising leg having a Idistal end thereof internally engaged with arespective one of Vsaid' tower legs for movement longitudinally alongthe interior of said tower leg to apply an erecting force to said towerin 'response to a swinging of said raising lleg about the proximal endthereof; and tractile power means connected to the distal ends of bothof said raising'legs to so swing the latter in unison.

7. In a self-erecting derrick, the combination of: a

horizontal base; a pair of 'legs joined fat their distal ends to form aninverted V-shaped tower, each of said tower legs having a longitudinaltrack formed therein; axially aligned pivots connecting theproximal'ends of said legs to said base for swinging movement ofsaidtower between said erect position and a prone position extendingforward-ly from sai-d pivots; a pair yof raising legs each having aproximail end universally pivoted on said base at a point forward of oneof said tower I'legs and means on the distal end engaged with arespective one of said tracks ffo'r .movement Valong saidr track toapply an erecting force to said tower in response to compound swingingoff said raising legs Yabout the-proximal ends thereof;

Vtractile power means connected between points adjacent. Y said towerpivots and the respective distal ends of said I,

raising legs to so swing the latter; and abutment and locking meansladjacent the proximal ends of said tracks and engageable with Vsaidraising legs toV prevent rearward movement of the tower past said erectposition and to lock the distail ends of the .raising legs in a fixedposition on the tower to thereby prevent forward movement of the towerwhile the locking means is effective.

8. in a self-erecting derrick, the combination of: a horizontal base; apair of legs joined at their distal ends to forman inverted V-s'hapedtower, each of said tower legs having a dog-leg track carried thereon,said track having a distal section disposed longitudinally of itsrespective leg and lan adjoining proximal section extending angularlyforward fromsaid distal section and downwardly therefrom when said leg,is erect; axially aligned pivots connecting the proximalendsof said legstosaid proximal end universally pivoted on saidlbase 'at a point forwardof one of said tower legs and 'means' on the distal endthereof engagedwith'a respective one -of said tracks" for longitudinal movementtherealong to apply` an erect` ing force to said tower in responseto'compound swing-L Cil from said pivots; a pair of `raisingdegse'achhavinga mg of said raising legs about the proximal' ends thereof;Vand tractile power means connected to the respective distal ends ofsaid raising legs to so swing the latter.

9. In a self-erecting derrick, :the combination of a horizontal base; apair Vof legs joined 'at their distal ends to form an inverted V-shapedtower,'each of said tower legs having a dog-leg track carried thereon,said track havingY a -distal section disposed longitudinally of' itsVrespectivel leg and an adjoining proximal section extending angu-llarly forward from'saiddistalV section and downwardly therefrom whensaid' 'le`g is erect; axially aligned pivots positionV and a Vproneposition Vextending forwardly from said pivots; a pair of raising legseach havin-g a proximal end universally pivoted `on said base at apointforward 'of one of said tower legs and means on the distal end lthereofengaged witha respective one of said tracks for longitudinal Vmovementtherealong to apply -anerecting force to saidtowerinV response tocompound swinging of said raising, legs about the proximal ends-thereof;tractile power means connected to the respective distal ends of saidraising legs -to-so swing the latter; and abutment meansv atthe-proximaltermini -of said tracks to limit the movement of saidlifting means therealong land prevent overtravel of said tower beyond asubstantially erect position. f

yl0. In a self-erectinggderrick, the combination of: a horizontal base;a pair of hollow columnar legs joined at their distal ends to'forrn aninverted V-shaped tower, each of said tower legs having a dog-leg trackcarried therein,

said track having a Vdistal section disposed substantially in the planeof the rearward face of its respective columnar leg and extendinglongitudinally in said plane, and an adjoining proximal sectionextending angularly forward from said distal section to a pointsubstantially in the forward surface of saidV columnar leg, said proxi-`mal section vextending downwardly when said legis erect; o axiallyalignedpivots` connecting the proximalends of' said' tower legs to saidbase for swinging movement of saidtower between an'erectposition and aprone position extending forwardly from said pivots; a pair ofYraisinglegseachjdisposed within a vrespective one of said tower'legswhenthe'latter is prone and Veach having a proximal' end pivoted on saidbase at a point forward of one of said tower legsrand track-engagingmeans on the distal end thereof engaged with a respective one of saidtracks forlongitudinal 4movement therealongto apply an erecting. force`to said tower in response t-o swinging of saidV raising legs about theproximal ends' thereof; and tractile power means connected betweenpoints adjacent Vsaid tower pivots and the respective distal ends ofsaid raising legs to ,so swing the latter.

lil. In a self-erecting derrick, the combination of: a

horizontal base; a pair of' legs joined at their distal ends distal endengaged with a respective one of said tower legs for movementlongitudinally therealong to apply an erecting force tosaid towerin.response to a swinging 1 of said raising leg labout the proximal endthereof; tracconnecting 'theV proximalrends -of said legs to saidv base,for swinging movement of said tower between an' erect` tile power meansconnected to the distal ends of both of said raising legs to so swingthe latter in unison; latch means carried lby said tower legs t-o lockthe distal ends of each of said raising legs to said tower when thelatter is in erect position to prevent movement of said distal ends ineither direction along said tower legs; and means connected to each ofsaid raising legs to selectively lengthen or shorten the same whereby toadjust the verticality of said tower when the distal ends of saidraising legs are locked to said tower as aforesaid.

`l2. In a self-erecting derrick, the combination of: a horizontal base;a pair of legs joined at their `distal ends to form an inverted V-shapedtower, each of said tower legs having a longitudinal track carriedthereon; pivots connecting the proximal ends of said tower legs to saidbase for swinging movement of said tower between an erect position and aprone position extending horizontally forward from said pivots; a pairof raising legs each having fa proximal end pivoted on said -base at apoint forward of and below a respective yone of said tower leg pivotsand track-engaging means on the dist-al end engaged with a respectiveone of said tracks for movement along said track to apply an erectingforce to said tower in response to swinging of said raising legs aboutthe proximal ends thereof; abutments at the distal ends of said tracksengageable by said track-engaging means to support said tower in saidhorizontal position thereof; and tractile power means connected to therespective distal ends of said raising legs to so swing the latter.

13. In a self-erecting derrick, the combination of: a support base; apair of hollow columnar legs joined at their distal ends and spacedapart at their proximal ends to form, when erect, an inverted V-shapedtower, said legs having longitudinally extending structural memberslying respectively in their rear and front faces; a first pair of pivotsconnecting the proximal ends of said rear face structural members tosaid base for swinging movement of said tower between an erect positionyand a prone position extending forwardly of said first pivots, each ofsaid tower legs having a track secured therein with the tracksconverging upwardly toward each other; a pair of raising legs, a pair ofuniversal pivot means on said base in front of and below said iirst pairof pivots pivotally securing the proximal ends of the raising legs tothe base, track engaging means on the distal ends of the raising legsengaged with respective ones of said tracks for movement along thetracks to apply an erecting force to the tower in response to compoundswinging of the raising legs as their distal ends move along saidtracks; and tractile power means connected to the raising legs to soswing the latter; each of said tracks having a distal end adjacent saidrear face and extending downwardly and for- Wardly to a proximal endposition at said front face so that the vertical distance between therst pair of pivots and the universal pivot means can be at a minimum toobtain a desired initial mechanical advantage and yet when the tower iserect, the raising legs are positioned to afford column loading of thetower.

14. In a self-erecting derrick, the combination of: a support base; atower having longitudinally extending front and rear structural members;first pivot means connecting the proximal ends of the rear structuralmembers to said base for swinging movement of the tower between an erectposition and a prone position extending forwardly of said first pivotmeans; track means secured to the tower to extend longitudinallythereof; at least one raising leg, second pivot means pivotallyconnecting a proximal end of said raising leg to said base at a pointforward and below said first pivot means, said raising leg having adistal end engaging said track means for movement of such distal endalong the track means to apply an erecting force to the tower inresponse to swinging movement of the raising leg about said second pivotmeans; and power means connected to the raising leg to so swing thelatter; said track means having a distal end adjacent said rearstructural member and extending downwardly and forwardly to a proximalend positioned at the front structural member so that the verticaldistance between the first and second pivot means can be at a minimum toobtain a desired initial mechanical advantage and yet when the tower iserect, the raising leg is positioned to afford column loading of thetower.

15. In a self-erecting derrick, the combination of: a horizontal base; atower including a pair of legs joined together at their distal ends andspaced apart at their proximal ends; a first pair of pivots connectingsaid proximal ends to the base for swinging movement of said towerbetween an erect position and a prone position extending forwardly fromsaid pivots; a pair of raising legs each having a proximal end thereofuniversally pivoted on said base at points forward of said tower legsand means on the distal end thereof engaged with a respective one of thetower legs for movement longitudinally therealong to apply an erectingforce to said tower in response to a swinging of said raising legs aboutthe proximal ends thereof; crown and traveling block means carried bysaid tower; a drawworks mounted on said base adjacent said first pair ofpivots and connected to said crown and traveling block means; forcetransmitting means connected between said crown and traveling blockmeans and the distal ends of said raising legs to swing the latter asaforesaid', and means connected to each of said raising legs to extendthe same and thereby cause a change in the verticality of the tower whenin erect position; said tower being open on the rear face thereofbetween said legs.

No references cited.

